Brake drum and method of making same



A il 10, 1934.

J. P. MAHONEY BRAKE DRUM AND METHOD OF MAKING SAME Filed April 7, 1930 VIINVENTOR. JOHN R MAONEY A TTORNEY Has Patented Apr. 10, 1934 PATENOFFICE BRAKE DRUM AND METHOD OF SAME John P. Mahoney, South Bend, Ind.,assignor to Bendix Brake Company, South Bend, Ind, a

corporation of Illinois Application April 7, 1930, Serial No. 442mm 4Claims. ((129-1522) This invention relates to brake structures and moreparticularly to improved brake drums.

Brake drums in general use consist of a blank of low carbon steelstamped or pressed into the desired shape. Deformable metal of thischaracter is chosen on account of the stamping operation. The resultingbrake drum is not entirely satisfactory because it does not possess ashigh a wear resistance and resistance to deformation as may be desired.

- Heretofore, considerable difficulty has been experienced in brakedrums due to the scoring thereof. This is especially so with the hardmolded linings at'present in use. It may be alleviated to some extent bythe use of drums having a high carbon content or formed of specialalloys designed to resist scoring. Such drums, however, are diiflcult toform and are costly. It is the aim of the present invention to overcomethese difliculties by the provision of a drum which will meet with thepresent day requirement.

The major object of the invention is to provide a drum having a flangeformed of high carbon steel and a disk portion of ordinary mild steel.

An important object of the invention is to provide a brake drum having aflange made up from a rolled section ofhigh carbon steel welded orotherwise secured to a disk of ordinary mild steel. r

Other objects and features of the invention will appear from thefollowing description taken in connection with the drawing, which formsa part of this specification, and in which:

Figure 1 is a side elevation of a drum embodying the invention,

Figure 2 is a section substantially on line 2-2, Figure 1, i Figure 3 isa side elevation of a coil of high carbon steel,

Figure 4 is a sectional view illustrating a modiflEation of the rim orflange,

Figure 5 is a sectional view illustrating another modification of theflange, and

Figure 6 is a plan view illustrating a bias cut in the flange.

Referring to the drawing for more specific details of the invention, 10represents a disk of ordinary mild steel having secured thereto as bybolts 11 or otherwise a flange or rim 12 of high carbon steel.Preferably, the rim is rolled in a spiral or coil 13 and sections areout therefrom and deformed to provide a continuous uniform flange orrim.-

The flange may be of any preferred type and may be secured to the diskby spot welding, as shown at it. It will, of course, be understood thatthe flange or rim may be provided with heat dissipating flanges 15 whichalso materially 6o strengthen the structure.

In practice, the disk 10 is stamped from a blank of ordinary mildsteelin the desired form and size and the rim or flange is made up inrolled sections of high carbon steel. These sections are rolled in theform of a spiral as clearly indicated in Figure 3 and are subsequentlycut to the desired length and the resulting lengths sprung or deformedto permit their assembh with disks 10 and provide a uniform brakingsur-' 7 face which will not be affected by the hard'molded linings, suchas are in general use.

If greater accuracy than usual is required in drum diameter, the highcarbon steel flange or rim may be cut on the bias as indicated at 16 7and the abutting ends of the flange or rim sp into position, so that theinherent tendency to spring apart due to the spiral convolution of thecoil substantially locks the ends together, hence the liability of therim having a tendency to warp, twist or otherwise distort the dish maybe avoided.

It will thus be seen that by utilizing different material for the disl:and flange of the w s r: and assembling these parts in the manner setforth, all of the advantages of the present type of struc ture withother advantages and features not heretofore possible, may be attained.It will, of course, be understood that various forms, other than thosedescribed may be used without deon parting from the spirit and scope ofthe invention.

Having thus described the various features of the invention, what Iclaim as new and desire to secure by Letters Patent is:

1. A brake drum comprising a disk, a normally spiral sheet metal rimhaving heat dissipating flanges and bevelled ends held together by thetension of the spiral characteristics of the ,rim and means securing theflange to the disk.

disk forming the head of the drum secured to the rim.

4. The method of constructing a brake drum which comprises rolling ahard metal flange member into spiral form, cutting the spiral ondiagonal lines into sections, springing a section into cylindrical formwith the diagonal edges in abutting relation, and securing to thesection a soft metal disk to form the head of the -drum.

JOHN P.. MAHONEY.

